In numerous industries, such as the aviation or space industries, it is common practice to use models in virtual reality. For example, a digital mock-up is often used to evaluate interference between various parts.
Similarly, modeling can be used to simulate human or robot actions in a defined environment in order to visualize the movement that a technician or a robot will need to make in order to undertake those actions, for example. This is useful for validating and optimizing accessibility to certain parts of a machine, such as the parts in an airplane engine, which parts require regular inspection and maintenance.
Thus, ease of access to the various elements of a device can be checked virtually as soon as the elements have been modeled, by means of a simulation using a virtual articulated object.
A virtual articulated object is a digital data set defining a dynamic system characterized by a plurality of elements that are articulated with a plurality of degrees of freedom.
Thus, at a given instant, the virtual articulated object may be defined by its position and orientation in a three-dimensional space and by values for the degrees of freedom of its joints. The data and the parameters defining the environment of the virtual articulated object can be stored in a digital data medium.
The use of a virtual articulated object for this type of application already exists.
An example is given in the article by Chedmail, Damay, and Le Roy, entitled “Réalité virtuelle, maquette numérique du produit, outils de distribution et partage de la conception” [Virtual reality, digital mock-up of the product, tools for distributing and sharing designs] (Journées Priméca, La Plagne, Apr. 7-9, 1999).
That article proposes a method of validating accessibility for assembling and disassembling an object in an obstructed environment using a model for the movement of two virtual articulated arms or of a virtual dummy in a virtual environment.
That method enables the dummy to move in an environment obstructed by obstacles without coming into collision with the obstacles.
However, the posture of the dummy, as it moves, can be arbitrary and that can lead to a collision between a given member of the dummy and the other members of the dummy. That reduces the accuracy with which movement of the dummy is modeled.